1.
S=x2+y2+2gx+2fy+4=0S=x^2+y^2+2gx+2fy+4=0 cuts x2+y24x4y4=0x^2+y^2-4x-4y-4=0 orthogonally and makes 6060^\circ with x2+y2+4x+4y+4=0x^2+y^2+4x+4y+4=0. Radius of SS is